The square of the wire diameter calculates the current, how to calculate the current by the square o

Three principles for choosing a wire:

1) Select the cross-section of the wire (safe ampacity) according to the heating conditions for the short distance and small load, and control the current with the heating conditions of the wire, the smaller the cross-sectional area, the better the heat dissipation, and the greater the current passing through the unit area.

2) Long-distance and medium-load on the basis of safe current carrying capacity, according to the voltage loss conditions to select the wire cross-section, long-distance and medium-load is not enough to not heat, but also consider the voltage loss, to ensure that the voltage to the load point is in the qualified range, electrical equipment can work normally.

3) On the basis of the qualified safe current carrying capacity and voltage drop, the large load is selected according to the economic current density, that is, the power loss should also be considered, and the power loss and capital investment should be in the most reasonable range.

Safe ampacities of the wire.

In order to ensure the continuous operation of the wire for a long time, the allowable current density is called the safe ampacity.

The general regulations are: copper wire selection 5 8a mm2; Aluminum wire selection 3 5a mm2.

The safe current carrying capacity should also be determined according to the ultimate temperature, cooling conditions, laying conditions and other comprehensive factors of the core use environment of the wire.

Under normal circumstances, the distance is short, the cross-sectional area is small, the heat dissipation is good, the temperature is low, etc., the conductivity of the wire is stronger, and the upper limit of the safe current carrying capacity is selected;

Long distance, large cross-sectional area, poor heat dissipation, high temperature, poor natural environment, etc., the conductivity of the wire is weaker, and the lower limit of safe current carrying is selected;

For example, the conductivity of bare wires is stronger than insulated wires, overhead wires are stronger than cables, cables buried in the ground are stronger than cables laid on the ground, and so on.

How much current is used to calculate how many square wires are used for lead fiber A: The standard copper wire is 6 amperes per square wire, (5 amperes for aluminum wire), so one square wire is 6 ampere current. The calculation formula is x square multiplied by 6a times 220v equals x square line allows the maximum load vertical load, power voltage x current principle can be used to calculate how much load power is allowed to use how much square wire is used.

For example, a square copper wire allows a load of 6A times 22ov 1320 watts, and a square wire allows a current of 6A to pass through.

The cross-sectional area of a wire, or known as the cross-sectional area of a wire, is usually expressed in terms of the current per unit area. The relationship between the square of the wire and the current can be calculated by Ohm's law

Current = Electric Blind State Voltage Resistance.

Among them, voltage refers to the voltage difference between the two ends of the wire, and resistance dust Shenbi pie is the resistance value of the wire, which can be calculated by factors such as the material, length and cross-sectional area of the wire. Assuming that the resistance of the wire is r and the voltage is v, then the current i is:

i = v / r

If the cross-sectional area of the wire is a, then the resistance r of the wire can be calculated by the following formula:

r = l / a

where is the resistivity of the wire and l is the length of the wire. From the above formula, we can derive the relationship between the square of the wire and the current:

i = v * a / l)

Therefore, if the cross-sectional area, length, voltage, and resistivity of the wire are known, the maximum current that the wire can withstand can be calculated.

The relationship between the cross-sectional area (square millimeters) and the current (amperes) of a wire depends on the resistance of the wire and the temperature of the conductor. In general, according to Ohm's law, the current i is equal to the voltage u divided by the resistance r, i.e., i = u r. The resistance r is related to the cross-sectional area a of the wire, the resistivity of the denier and the length of the wire l, and the tongbi shed is often calculated by r = l a.

Therefore, if we know the cross-sectional area a and voltage u of the wire, we can calculate the resistance r and then deduce the magnitude of the current i according to Ohm's law, i.e., i=u r=u*a ( l). It should be noted that the resistivity corresponding to different wire materials and working conditions is different, and it needs to be calculated according to the specific situation.

The conductivity of a wire is determined by parameters such as its material, cross-sectional area, and length, and usually we use the cross-sectional area of a conductor to evaluate its conductivity. The magnitude of the current is generated by the movement of electrons in the wire, so when the electrons pass through the wire, the magnitude of the current also depends on the conductivity of the wire, that is, the size of its cross-sectional area. Therefore, when calculating the current of a wire, the current value can be measured by an ammeter according to the cross-sectional area of the wire.

The specific calculation formula is: current = voltage resistance. It should be noted that in order to avoid wire overload and safety problems, it is necessary to choose a suitable dry wire and a suitable current rating according to the actual needs.

The corresponding currents of each square line are:

The rated current of 1 square wire is about 5A.

The rated current of a square wire is about 10A.

The square wire has a current rating of about 15A.

The square wire has a current rating of about 20A.

The rated Wichai current for 6 square wires is about 30A.

The rated current of 10 square wires is about 60A.

The current carrying capacity of the wire is related to the surface of the wire cut-off, and is also related to the material, model, laying method and ambient temperature of the wire, and there are many factors that affect it. In addition, the length of the line, the arrangement, the surrounding heat dissipation conditions, and the factors of line voltage reduction all affect the actual flow rate.

Wire Squared Calculation Method:

Knowing the square of the wire, calculate the radius of the wire using the formula for finding the area of a circle:

Number of wires squared (mm²) Pi (square of the radius of the wire in mm).

Knowing the square of the wire, the calculation of the wire diameter is also like this, for example: the wire diameter of the square wire is: , and then the square is obtained by the millimeter, so the line of defense refers to the light line diameter is: 2 mm mm.

Knowing the diameter of the wire, calculating the square of the wire is also calculated using the formula for finding the area of a circle:

The square of the wire Pi (4 squared of the wire diameter.)

The size of the cable is also nominal in terms of squares, and the stranded wire is the sum of the cross-sectional areas of each wire.

The formula for calculating the cross-sectional area of the cable:

The square of the wire radius (mm) and the number of strands.

Such as 48 strands (each strand of wire radius in millimeters) square wire: square <>

The standard formula for calculating Guess Na is i=u r, where u is the input voltage of the megawheel and r is the resistance of the wire, which can be calculated according to the formula for calculating the resistance (related to the length and cross-sectional area of the mega wire).

How to calculate the length of the wire and the size of the current.

r=ρ*s*l.Resistivity, s = cross-sectional area of the wire, l = length of the wire. i=v/ρ*s*l

Does l refer to the length of the wire?

What do p and s mean, respectively?

l is the length of the wire.

p is the resistivity.

s is the cross-sectional area of the wire.

What does resistivity mean.

Resistivity is resistivity.

Resistivity is a physical quantity used to express the electrical properties of various substances. The ratio of the product of the resistance to the cross-sectional area and the length of the original (20°C at room temperature) made of a certain substance is called the resistivity of the substance. Resistivity has nothing to do with the length, cross-sectional area and other factors of the conductor, but is the electrical property of the conductor material itself, which is determined by the old material of the conductor and is related to the temperature.

For example, at 20°C, the resistivity of copper is in ohms.

Summary. The formula for calculating the length of wire current, R=PL is the resistance, P is the constant, L is the length of the wire, S is the relationship between the length of the wire and the current in the cross-sectional area of the wire, according to the electrician, a formula of resistance, R=PL S, R is the resistance, P is the constant, L is the length of the wire, S is the cross-sectional area of the wire, so the longer the wire, the greater the resistance, the more difficult it is to heat up through the current, and there is current loss, so we are using electrical equipment, and electrical appliances, the device should be closer to the power supply, so as to reduce the loss of line resistance.

The formula for calculating the length of wire current, R=PL is the resistance, P is the constant, L is the length of the wire, S is the relationship between the length of the wire and the current, according to the electrical engineering, a formula of the electric resistance, R=PL S, R is the resistance, P is the constant, L is the source degree of the wire length, S is the cross-sectional area of the wire, so the longer the wire, the greater the resistance, the more difficult it is to heat up through the current, and there is current loss, so we are using electrical equipment, and electrical appliances, the device should be closer to the power supply, It is good to reduce the loss of line resistance.

The standard formula for calculating Guess Na is i=u r, where u is the input voltage of the megawheel and r is the resistance of the wire, which can be calculated according to the formula for calculating the resistance (related to the length and cross-sectional area of the mega wire).

1. There are two kinds of square numbers of cables: one is calculated according to the diameter, that is, the flat and blind square, and the other is calculated according to the DC resistance, which is more troublesome and the experimental data are the majority.

2. Generally speaking, the empirical carrying capacity is when the grid voltage is 220V, and the empirical carrying capacity per square wire is about 1,000 watts.

3. Each square of copper wire can carry kilowatts, and each square of aluminum wire can carry kilowatts. Therefore, an appliance with a power of 1 kilowatt requires only one square copper wire.

4. Specific to the current, when the short-distance power transmission is carried by the copper wire, the current can be 3A to 5A per square meter. The heat dissipation conditions are good to take 5A square centimeters, and it is not good to take 3A square millimeters.

5. Conversion method: know the square of the wire, calculate the radius of the wire and calculate it with the formula of finding the area of the circle

Number of wires squared (mm²) (The square of the radius of the wire.)

Summary. Hello, here is the answer for you: the current length calculation formula of the wire, r=pl is the resistance, p is the constant, l is the length of the wire, s is the relationship between the length of the wire and the current, according to the electrician, a formula of resistance, r = pl s, r is the resistance, p is the constant, l is the length of the wire, s is the cross-sectional area of the wire, so the longer the wire, the greater the resistance, it is difficult to heat up through the current, there is current loss, so we are using electrical equipment, and electrical appliances, devices should be closer to the power supply, It is good to reduce the loss of line resistance.

Hello, here is the answer for you: the current length of the wire calculation formula, r = pl is the resistance, p is the constant, l is the length of the wire more than the positive degree, s is the relationship between the length of the wire and the current of the wire cross-sectional area, according to the electrician, a formula of resistance, vertical guess r = pl s, r is the resistance, p is the constant, l is the length of the wire, s is the cross-sectional area of the wire, so the longer the wire, the greater the resistance, the current is difficult to heat up, there is current loss, so we are using electrical equipment, and electrical appliances, The device should be closer to the power supply to reduce line resistance loss.

Related information: The standard calculation formula is i=u r, where u is the input voltage, r is the resistance of the wire, and the call can be calculated according to the calculation formula of the electric resistance (related to the length and cross-sectional area of the wire).